As a demo of the ArcGIS API for Flex, ESRI has a new page that lets you create an embeddable/shareable map of demographic data by US county. Only seven datasets available now:

Median Household Income

Population Change 2000-2009

Population Density (per sq. mile)

Median Home Value

Unemployment Rate

Average Household Size

Median Age

Map creation is trivially easy – select the demographic dataset from a dropdown, zoom the map to the desired extents, set a map size in pixels, and you’re done; links to a map with your parameters, and code for an embeddable map, are generated automatically. Here’s an embedded map, scrollable and zoomable; unemployment rate is the default dataset, but you can choose other sets with the dropdown menu at upper right:

More datasets would be nice, as would control over colors and ranges …